You won’t get rich as a teacher, right? That’s no longer true for a small but growing number of educators who are making big bucks selling their lesson plans online. On a peer-to-peer site called TeachersPayTeachers (TPT), Georgia kindergarten teacher Deanna Jump has earned more than $1 million selling lesson plans — with names like “Colorful Cats Math, Science and Literacy Fun!” — for about $9 a pop. Since the site launched in 2006, 26 teachers have each made more than $100,000 on TPT, which takes a 15% commission on most sales. In August, Jump became the first on TPT to reach $1 million. Her success has been aided by the thousands of followers of her personal blog who get notified each time she retails a new lesson. Another reason she thinks her stuff sells so well: “I’ve used it in my classroom,” says Jump, who just kicked off her 16th year of teaching. “I know it works.”

Standards and testing may hog the spotlight in education, but they spell out only what students should be able to do, not how to get kids to learn those skills. Lesson plans are teachers’ tools: lend someone a better hammer, and he’ll do a better job. But a lousy carpenter can’t fake it even with the greatest tools money can buy, and the lesson plans that come with textbooks often aren’t very engaging or aren’t in line with the Common Core State Standards that 45 states recently agreed to adopt. There’s a lot of concern among teachers about meeting these standards, particularly since more states have started tying teachers’ evaluations to their students’ performance. And the rising popularity of lesson-sharing sites like BetterLesson, which in June signed up its 100,000th teacher, points to one of education’s most ironic problems: teachers don’t share very much with their colleagues. Yes, there are master teachers who help coach less effective co-workers, but faculty members still get relatively little time with one another. Schools don’t prioritize it, and teachers’ contracts spell out their day down to the minute. What we consider schools are often just loose confederations of independent contractors, each overseeing his or her own classroom.

The need for more collaboration helps explain why the American Federation of Teachers (AFT), the U.S.’s second largest teachers’ union, launched a site this summer called Share My Lesson, where teachers can get free lesson plans. It’s unclear how the union’s corporate partner, TES Connect, intends to make money from the venture or whether the Deanna Jumps of the world will post their material on the site, given that it doesn’t pay for content. “If teachers don’t want to share, they don’t have to,” says AFT president Randi Weingarten. “But this is a huge opportunity for teachers to work with each other to improve our craft.”

That may sound like a raw deal until you think about what’s been happening in higher education, where more and more colleges are getting professors to put their syllabus and, more recently, videos of their lectures online. But it’s a new frontier in the long insulated K-12 world. And as a legal matter, it’s not cut and dry: if teachers produce a lesson as part of their regular work, even if it’s on their own time, does their school or school district have any right to profits from it? In 2004 a federal court in New York said yes. Look for more litigation as the money involved with these sites grows.

Of course, not everyone thinks crowdsourcing lesson plans is the smartest solution, including one of the companies that lets teachers download free lesson plans à la carte. BetterLesson’s main goal, which has interested several venture-capital firms, is selling schools and districts customized curriculums in multiweek chunks that come with daily lesson plans and work sheets. Founded by a Teach for America alum, BetterLesson summed up its philosophy in a recent post on the company’s blog: “Give a man a random resource, he teaches for a class period. Give him inspiring examples of complete units on poetry, narrative writing and sentence structure, his next few months of instruction are transformed.”

Regardless of who foots the bill for more-effective lesson plans, this sort of professional sharing is long overdue. Too many teachers are on their own. It’s a sink-or-swim system, as Weingarten has often noted, but it doesn’t have to be that way.

Rotherham is a co-founder and partner at the nonprofit Bellwether Education, a national non-profit organization which, among other activities, does paid consulting work for clients including school districts, charter schools, and educational organizations around the country. The views expressed are solely his own.